That is correct.

There are still plenty of antique systems still operating around here and many are only controlled by pressure controls.

Most of the low pressure switches i set for temp control usually need a slight adjustment on the diff to achieve the desired effect.

Doesnt take long to watch it reach cut out. Beats coming back to move the diff slightly at a later date.

It also amazes me how many times you find a system controlled by t/stat that hasn't had the pressure control set up to control the icing of the coil.It seems some people would rather install a defrost timer instead of turning a screw.